Currently, consumers have a wide variety of options—ranging from nonsurgical to surgical—aimed at combating the unwanted effects of aging skin and for furnishing a more youthful appearance. Nonsurgical methods include the topical use of moisturizers and keratolyic agents, cleansers, sunscreens and sunblocks, antioxidants, serums, exfoliants, and makeup. Surgical methods include chemical peels, the use of botulinum toxin or fillers (e.g., bovine collagen, silicone, and hyaluronic acid), and plastic or laser surgery. However, although the majority of the aforementioned alternatives provide at least one skin-care benefit, they are not without their drawbacks as well.
For example, many topical skin treatments contain ingredients that can clog pores, promote acne, trigger allergies, cause irritation, and block natural water evaporation, thereby disturbing the skin's normal healthy balance. Specifically, although retinoid therapy has shown promise in the treatment of skin-aging maladies, certain retinoids such as tretinoin and tazarotene, have been shown to cause burning, scaling, and dermatitis thereby limiting their acceptance by many patients. And because alpha hydroxy acids, a common additive to numerous skin care products, work mainly as an exfoliant whereby outer stratum epidermal cells are prematurely sloughed off, the resulting newly exposed cells are susceptible to irritation and sun sensitivity. Even ingredients as seemingly benign as emollients and moisturizers (e.g., mineral oil, petrolatum and lanolin), have been known to cause burning, stinging, redness, or irritation in some cases. Lastly, some commercially available compositions contain ingredients that are supported by pseudo-scientific claims, which are misleading or unsupported by scientific evidence, and are in fact hazardous to the skin.
Alternatively, although chemical peels help to improve the appearance of aging and dull skin by stimulating cell turnover and cell function in the layers just below the treated top layer of the skin, because acids are commonly used during the procedure, the patient may experience a burning sensation. And, depending on the compound used, recovery times may take up to four weeks during which the skin may ooze and scab. Finally, although not extremely common, the procedure can cause infection, permanent scaring or discoloration, and excessively dry skin that peels too often.
In addition, many modern treatments for aged skin—including the use of peptides and other actives that stimulate new collagen and connective tissue production—have been shown to have a limited temporary effect. As a result, once daily use has ceased, the skin will revert to its previous aged looking condition. Many of the limitations are a product of the peptide's reduced length, which in turn contributes to their generally poor specificity, their conformational flexibility, and their inability to fold into secondary, tertiary, and quaternary structures. Furthermore, peptides are hydrophilic. Therefore, they are unable to penetrate easily the lipophilic stratum corneum layer of the epidermis. Despite their hydrophilicity, however, peptides are generally unstable in water-based formulations, as the water breaks down the peptide bond, rendering it inactive. Moreover, should peptides be absorbed, the abundant presence of enzymes found in the skin can also break down peptide bonds.
In addition, recent scientific studies on normal skin renewal processes have shown that NF-κB plays an integral role in the turnover of skin tissues; human skin is always being turned over, that is renewed. And, NF-κB is in large part responsible for the removal of the old skin, so it can be replaced by the new skin. As the skin ages, the skin's natural homeostatic condition changes to that typified by an older skin phenotype, as compared to youthful phenotypes. One of the controlling factors is an increase in NF-κB, which causes the skin to look older, thinner, dryer, inflamed, and more wrinkled. This aging process is accelerated by many different environmental factors, including exposure to sunlight, pollution, low humidity, and smoke. These external insults cause disruption in the skin's normal homeostatic mechanisms, which accelerate the worsening appearance of aged looking skin.
In light of the deficiencies and drawbacks prevalent in the prior art, it is readily apparent that there continues to be a significant need for skin care compositions which not only improve and maintain the health and physical appearance of the skin but are also safe, stable, long-lasting, and effective in treating the appearance of wrinkles, fine lines, pores, discolorations, sallowness, and other forms of undesirable skin surface textures.